摘要
建立了催化氧化荧光法间接测定叶酸的新方法。在pH5．0的HAc—NaAc缓冲溶液中，Co2＋催化KIO。氧化叶酸产生强荧光，以262nm为激发波长，在445nm处测定叶酸的氧化产物蝶呤-6-羧酸的荧光强度，研究了反应的适宜条件及动力学参数，并探讨了反应机理。在优化实验条件下，叶酸浓度在1．0×10^-8-1．0×10^-5mol／L范围内与荧光强度呈良好线陆关系，回归方程为△IF=10．82c（μmol／L）＋2．867，相关系数r=0．9985，方法的检出限为5×10^-9mol／L。对5×10^-7moL／L叶酸标准溶液进行11次平行测定，相对标准偏差（RSD）为0．1％。该法使用Co2＋为催化剂，大大提高了方法的灵敏度。方法用于蔬菜中叶酸的测定，加标回收率为93％-104％，6次测定的相对标准偏差为0．98％～2．1％，结果令人满意。
Based on the catalytic effect of cobalt （ Ⅱ ） on the oxidation of folic acid by high potassium iodate in pH 5.0 HAc - NaAc buffer solution. A new catalytic oxidation fluorometric method for indi- rectly determination of folic acid was proposed. The amount of folic acid Was obtained by determining the fluorescence intensity of pterin-6-carboxylic acid, the oxidation product of folic acid, at exciting wavelength of 262 nm and measuring wavelength of 445 nm. The optimum reaction conditions and kinetic parameters of this reaction were investigated, and the reaction mechanism was studied. Under the optimal conditions, the folic acid concentration within a range of 1.0 ×10^-8- 1.0 ×10^-5 mol/L had a good linear relation, the regression equation was AIF = 10. 82c（μmol/L） ＋2. 867 with a correlation coefficient of 0. 998 5. The detection limit of method was 5 ×10^-9 mol/L, and the relative standard deviation（RSD, n = 11） for 5 ×10^-7 mol/L folic acid was 0. 1%. The developed method with cobalt（ Ⅱ ） as catalyst, showed high sensitivity, and was applied for the detection of folic acid in vegetable with spiked recoveries of 93% -104% , and RSDs of 0.98% -2. 1%.
出处
《分析测试学报》
CAS
CSCD
北大核心
2010年第3期272-275,共4页
Journal of Instrumental Analysis
基金
运城学院2009年度院级基础研究资助项目(JC-2009005)
关键词
催化氧化
荧光光度法
叶酸
蔬菜
catalytic oxidation
fluorometry
folic acid
vegetable
